The principal reason you might fear for this new BMW M5 is weight, with its four-wheel drive system, but M division has been very canny.

The mixed-metal underbody construction of the current 5 Series, together with the adoption of some lightweight body panels (aluminium bonnet and front wings, roof in CFRP), has allowed the firm to bring the F90 M5 in at a kerb weight that’s 15kg lighter than that of its immediate predecessor.

An unbelievably good package, this M5, although I’m unconvinced by the steering. The 275-section front tyres are easily distracted and the rack weights up inconsistently.

By doing that, BMW neatly escapes accusations that it is wilfully adding dulling heft to this car, although it won’t reveal how much lighter the M5 might have been if it had retained its traditional drive layout. Still, a four-wheel-drive saloon car coming in lighter than the two-wheel-drive one it’s replacing is sufficiently clever engineering to get a big thumbs-up from us.

The car’s M xDrive four-wheel drive system is rear-driven as a default, sending torque to the front axle as needed via a chain drive and electronically actuated clutch. Between the rear wheels, meanwhile, is BMW’s Active M differential, which can vary from 100% open to 100% locked in a split second. And conducting the interactions and combinations of those systems, together with those of the adaptive damping and dynamic stability control systems, is a new electronic ‘chassis brain’ that has the power to overrule the ECUs of each individual system to ensure the M5 is behaving as its driver intends.

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The 4.4-litre V8, meanwhile, is in receipt of new turbochargers, a higher-pressure fuel injection system and a new exhaust since its adoption in the last M5. And putting customer preferences to one side, the engine’s new peak outputs (591bhp and 553lb ft – both likely to rise a little for the M5 Competition coming later this year) were enough to convince the car’s chassis engineers that a four-wheel drive system has become an absolute necessity.

The chassis engineers have totally respecified the 5 Series’s double-wishbone front suspension right down to the metalwork and bushings, adding track width up front while they were at it. At the rear, the M5’s multi-link set-up gets new toe links, new lower wishbones, stiffer anti-roll bars and stiffer bushings. Bracing has been added to both subframes and mounting points reinforced.

You can upgrade the car’s standard steel and aluminium brakes to larger carbon-ceramic stoppers, which save 23kg in unsprung mass – and our test car had them fitted.